/*
 * coddays.c - 求出温度低于零度的天数的百分率
 */
#include <stdio.h>
int main(void)
{
    const int FREEZING = 0; 
    float temperature;
    int cold_days = 0;
    int all_days = 0;
    printf("Enter the list of daily low temperatures.\n");
    printf("Use Celsius, and enter q to quit.\n");
    while (scanf("%f", &temperature) == 1) {
        all_days++;
        if (temperature < FREEZING) {
            cold_days++;
        }
    }

    if (all_days != 0) {
        printf("%d days total: %.lf%% where below freezing.\n", 
                all_days, 100.0 * (float)cold_days / all_days);
    } 
    if (all_days == 0) {
        printf("No data entered!\n");
    }
    return 0;
}
